The present invention relates to a press mold for press molding a large plate-shaped glass substrate molded object, and a pressing method for the glass substrate.
As fiber alignment components, there are known fiber arrays which are used to connect fibers with other optical components, and MT connectors which are used to connect fibers with one another. These connecting optical components are fabricated using a glass substrate having fiber securing grooves. The molded object for a glass substrate having such grooves on its surface is generally molded using a press mold consisting of an upper mold and a lower mold.
That is, the glass substrate is fabricated by flowing molten glass material into a mold for press molding. In press molding for a plate-shaped glass substrate, the glass substrate is normally fabricated by means of a two-step molding process consisting of a first step of molding from molten glass to a plate-shaped glass substrate, and a second step of molding more precisely by re-heating the glass substrate obtained in the first step.
Here, in the case of molding a glass substrate having grooves on its surface as described above, in the second step, a so-called re-heat press process, molding is performed using a press mold consisting of an upper mold and a lower mold each having a groove-shaped mold surface. In recent years, a large glass substrate molded object has been requested in terms of operation efficiency and cost.
If, however, the glass substrate molded object is made as large as, for example, two inches or more in diameter, a tensile force of a fixed value or more is exerted between the molds and the glass substrate molded object when the mold is released after pressing, and as a result, the glass substrate molded object and the molds may be damaged. Also, when the glass substrate size is made larger and the thickness is made thinner, the tensile force tends to become larger.
The present invention has been achieved in the light of above-described conventional problem, and is aimed to provide a press mold for glass substrate and a pressing method capable of applying uniform pressure to an entire mold surface and thereby preventing a molded object or a mold from being damaged and eliminating variance in pressure on the mold surface of the mold as far as possible on molding a large glass substrate molded object.